Along the Woluwe and the Hollebeek there used to be many ‘broeken’: wet, marshy meadows. From early September to the end of October the poor were allowed to graze their cattle there freely. The sources mention the Dyeghem broec (1644) and, nearby, the Harenbroec, the Machelen broec and the Vilvoorden broec. The Broekstraat, an old link to the Hamweg and the Senne, still recalls them.
Diegem had its Langbroek, from Zaventem along the Woluwe as far as the castle; the name Lambroek may be a corruption of it. Opposite the Duivenmolen lay the Cortenbroek, along the Hollebeek, and on the lower Woluwe, towards Machelen, the Thiendebroek, whose tithes went to the abbey of Kornelimünster.
Ponds for mills and paper
The ponds were not only for fish. At the Broekmolen a channel caught the water of the Woluwe and led it to a pond across the road; a second channel carried the used water away to the Hollebeek. In this way the paper mill always had enough clean water, and the owner paid double quit-rent for the two channels. Around 1606 Gillis de Smet likewise led the water of his pond at ten Bossche over the Hollebeek and the Woluwe to his paper mill.
A ribbon of ponds
Until the 20th century a ribbon of ponds lay between the village and Nijpezele: in the park of the De Reine castle, at the Donjon, on the castle estate and later at the Alpiflora ornamental nursery in Diegem-Lo. When the Woluwe was covered over in the 1930s, many ponds were reduced or filled in. In May 1943 the castle pond was still a bathing place for young people.
In 1956 the municipality laid out a park with a pond on the former castle estate, with the Cleyne Molen in the background; part of the old castle pond became a football pitch, next to the burnt-out castle. The Alpiflora ponds disappeared in 1972 when the motorway interchange was enlarged.